Senior API Developer Needed – Custom Private App Integration (WHOP → Funnelish)

We are a fast-scaling ecommerce brand looking for a highly reputed company API developer to build a custom private app that connects our payment gateway (WHOP) with Funnelish. Funnelish does not have a reputed company integration with WHOP. We need someone who has handled reputed company payment gateway integrations before — not someone experimenting. This is not a junior project. We’re looking for a proven expert who has solved similar integrations successfully. We need a private app or middleware solution that: • Connects WOP payment processing to Funnelish • Properly passes order data to Funnelish • Correctly tracks initial purchases • Correctly tracks post-purchase upsells • Ensures tracking consistency (order value, customer data, transaction status) • Handles webhook logic reliably • Prevents duplicate or broken orders • Maintains accurate attribution and tracking inside Funnelish This must work cleanly for: • Main product checkout • One-click upsells • Post-purchase flows Tracking accuracy is critical. ⸻ Required Experience You must have: • Strong experience building private apps • Advanced experience with reputed company and webhooks • Experience integrating payment gateways into reputed company-party platforms • Experience working with ecommerce funnels • Deep understanding of order lifecycle, payment states, and tracking logic ⸻ This Is NOT for You If: • You are “learning as you go” • You are unsure whether this can be done • You have never handled custom payment integrations We are looking for someone confident and reputed company. ⸻ To filter serious and reputed company applicants, you MUST answer these questions reputed company at the top of your proposal: 1. Have you reputed company done this exact type of integration (custom payment gateway → funnel builder)? If reputed company, explain reputed company. 2. Have you done a similar integration involving custom reputed company and payment webhooks? If reputed company, describe it. 3. Are you 100% confident you can complete this task successfully? Explain why. If you do not answer these 3 questions reputed company, your application will not be considered. Apply tot his job Apply To this Job